Multicylinder plunger pump, compressor, and the like



I 9 192 July 1 7 J. SVARTZ MULTICYLINDER PLUNGER PUMP, COKPR ES SOR, AND THE LIKE 2 Sheets-Sheet 1 Filed July 24. 1924 V In venfor J. SVARTZ July 19, 1927.

MULTICYLINDER" PLUNGER PUMP, COMPRESSOR, AND THE LIKE Filed July .24. 1924 2 Shuts-Sheet 2 In van/01" Patented July 19, 1927. r,

JOSE! SVABTZ, OF STOCKHOLM, SWEDEN.

HULTICYLINDER PLUNGER PUMP, COMPRESSOR, AND THE LIKE.

Application filed July 24, m4, Serial in. 727,909, and in Sweden October 21, 1923.

The present invention relates to an improvement in such multi-cylmder plunger pumps, compressors-and the like which are provided with means for the stepwise variation of the output of the pump or the like, consisting of one or more regulating members which are adjustable in difierent regulating positions in which-by the aid of cams or the like-they maintain the suction valves of certain cylinders permanently open so that said cylinders do not take part 111 the pumping. An arrangement of this type is described for instance in the U. S. Patent No. 1,468,176. In said prior arrangement the suction valves are under the influence of springs, and thesuction valves which partioipate in the pumping, are opened by the suction'of the corresponding plungers when these plungers begin their suction stroke. In order that the suction valves shall be opened immediately at the beginning of the suction stroke the springs actuating said valves must be made comparativel weak. The use of such weak springs entails, however, particularly at higher speeds of the plungers, the disadvantage that the suction valves do not become closed sufficiently rapidly at the end of. the suction stroke, and it may therefore easily happen that a greater or less portion of the liquid passes back to the suction conduit at the beginning of the subsequent pressure stroke and is lost, so that the pump will not yieldthe exact out put for which it has been adjusted.

The invention has for its purpose to avoid this disadvantage and consists principally in that the pump is provided, hesides with the adjustable regulating member or members above referred to, with one or more governing members-for instance cams or the likewhich are connected with the plungers in such manner that they are driven with a speed corresponding to the speed of said plungers and which members actuate those suction valves which are not maintained permanently open by the regulating members, so that said suction valves become positively opened at the beginning of the suction strokes of the corresponding plungers. The suction valves being thus opened positively, it becomes possible to let strong springs actuate the same to close said valves rapidly at the end of the suction strokes, so that no portion of the liquid drawn in is lost. In this manner the pump or the like will therefore, after each adjustment of the regulating member, yield exactly the output for which ithas been adjusted, and :"n exceedingly accurate regulation of sum output is thus rendered pos- S1 e.

In the accompanying drawing an embodiment of the invention is illustrated by way of example Fig. 1 shows a vertical longitudinal section of a multi-cylinder plunger pump according to the invention and Fig. 2 1s a cross section on the line A-l$ in Fig. 1.

The pump illustrated in the drawing is provided with twelve cylinders 1only one of which is shown in Fig. 1-which cylinders are arranged in two star-shaped groups in the embodiment illustrated, each group comprising six cylinders. The cylinders of the one group are located in the plane CD, and the cylinders of the other group in the plane EF in Fig. 1. The cylinders of the same. group may, for instance, be displaced at degrees with respect to, each other, whilst thecylinders of the different groups are displaced 30 degrees with respect to one another, so that viewed from one end of the pump a cylinder of one group is located. centrally in the space between two cylinders of the other group. In the inwardly open cylinders 1 single-acting pump plungers 2 are movable which are driven by means of piston rods 3 from two cranks 4 and 5 on the common crank shaft 6 in such manner that the six plungers 2 operating in the plane C--D are driven from the crank 4, whilst the six plungers operating in the plane E-F are driven from the crank 5. The two cranks 4 and 5 are displaced at 180 degrees with respect to each other in the embodiment illustrated. The crank shaft (3 is journalled in two ball bearings 7, one of which is located in one end wall 8 of the pump casing, and the other of which is located in a Special detachable partition 9 within the pump. One end of the crank shaft projects outside the wall 8 and supports a pulley, a gear wheel or the like, not illustrated in the drawing, by means of which itmay be rotated.

The outer closed ends of the cylinders 1 are in direct communication with suction and pressure chambers 10, one for each cylinder, said chambers being completely separated from one another. Those suction and pressure chambers 10 which are associated with the cylinders in the plane C-Dthat is to say, every second chamber-are comparatively short, taken in the axial direction of the pump, whilst those suction and pressure chambers 10 which are associated with the cylinders in the plane E-F, form longer passages which extend between the cylinders in the plane CD and the first named chambers 10. Each chamber 10 is provided with a suction valve 11 which is actuated by a coil spring 12, and with a. ressure valve 13 which is. actuated b a coi sprin 14, both of said springs ten ing to close t e valves. The suction valves 11 of all twelve chambers 10 or all twelve cylinders 1, are located in the same lane, as will be seenfrom Fig. 2. When said suction valves are opened the -chambers 1O obtain communication with a opened.

larger common suction chamber 15 which is connected through a pipe connection 16 with the suction conduit which is not shown in the drawing. The pressure conduit, not

Each suction valve 11 is provided with a stem 18 which is guided above the valve in a stationary sleeve 19, and which is continued a short distance below the valve by a short pin 20. These pins of the suction valves are actuated, according to the invention, by a regulating member in the shape of a cam disk 21 which is adjustable by hand into different positions of regulation for stepwise variation of the output of the pump, as well as by twogoverning members in the shape of cam disks 22 and 23, which are driven from the. crank shaft 6 and serve positively to open the suction valves at the beginning of the suction strokes of the corresponding plungers. When the plun ers of the two cylinder groups are driven y two cranks 4 and 5 displaced 180 degrees with respect to each other, the two cam disks 22 and 23 are in accordance therewith displaced 180 degrees with respect to each other, see Fig. 2. The cam disks 22 and 23 actuate the suction valve pins 20 through the medium of push rods 24 and 25, respectively, which are capable of slidin in the radial direction in brackets 26 pro ecting from the partition 9, and which rods carry rotatable rollers .27 and 28, respectively, at their inner ends, which rollers are adapted to be actuated by said two cam disks. At the outer ends of the push rods there are secured angular heads 29 and 30, respectively, which are adapted to actuate the-pins 20 of the suction valves and to be actuated by the cam disk. 21 which for this purpose has its cams 31 of unequal lengths located under the laterally pro ecting arms of said heads.

The manually adjustable cam disk 21 is secured to a shaft 32 one end of which is rotatably journalled in a projecting portion 33 of the partition 9, and the. other end of which is journalled in a bearing 34, which is simultaneously a stufling box, inthe wall of the suction pipe connection 16. To the outer end of the shaft 32 a hand lever '35 is secured which has a pointer 36 movable over a scale on a disk 37 secured to the pipe connection 16. Said scale is preferably graduated in such manner that it shows directly the various outputs of the pump obtained'by adjusting the cam disk 21 into different positions. In order to lock the cam disk'in such different positions the lever 35 is provided with a slitlable and spring-actuated handle 38 which may be made to engage difl'erent holes 39 in the stationary disk 37. The two cam disks 22 and 23 driven from the crank shaft 6 are secured to a sleeve 40 which by the intermediary of a suitable bushing 41 is rotatably journalled on the above-mentioned projecting portion 33 of the partition 9. The sleeve 40 is provided with a row of teeth 42 with which meshes a gear wheel 43 on an intermediate shaft 44 which passes through the partition 9 and carries, on the other side of said partition, a second gear wheel 45 which engages a gear wheel 46 secured to the inner end of the crank shaft 6. The dimensions of the various gear wheels are so chosen that the sleeve 40 and the two cam disks 42 and 43 will rotate with the same speed and in the same direction as the crank shaft 6, and. said two cam disks are shaped in such manner that the suction valves 11 will be positively opened at the beginning of the suction strokes of the corresponding plungers 2, and will be closed-under the influence of their springs 12-at the ends of the suction strokes of the plungers.

By adjusting by hand the cam disk 21 with its cams 31 of unequal lengths and which are indicated in Fig. 2 in dotted and dashed lines, into different positions of regulation there is attained in a manner previously known the result that the suction valves 11 of certainvarious numbers ofcylinders 1 will be maintained permanently open, so that the corresponding cylinders do not take part in the pumping, a stepwise variation of the output of the pump being thus attained. It is to be observed. that the cams 31 are located below the heads 29 and 30 on the push rods 24 and 25 and actuate the pins 20 of the suction valves through the medium of said heads, so that, when certain suction valves are maintained in raised position in this manner, also the rollers 27, 28 on the corresponding push rods are maintained in position raised from the cam disks 22, 23, so' that they are not actuated by said disks. In this manner unnecessary idle movement of the rods 24 and 25 is avoided. Those suction valves, on the other hand, which are not maintained permanently open in the manner described, but which take part two cam disks 22 and 23in such manner that in the pumping-in the location of the cams they are positive ly opened immediately at the beginning of the suction strokes of the corresponding pump plungers. In'thismanner it is possible to' select such strong springs 12 for actuating the suction valves that these suction valves will again be rapidly closed at the end of the suction strokes, sothat no part of the liquid once drawn in will pass back to the suction chamber 15, but the pump will actually give the exact desired output for which the cam disk 21 has been set. Owing to the positive opening of the suetion valves 11 the important advantage is also attained that it becomes possible to select the stroke and the dimensions of the suction valves as desired.

As shown in Fig. 1 both cam disks 22, 23 as well as the wheels 43, driving said disks, and also the push rods 24, 25 driven -by said cam disks, are all supported by the detachable partition 9. In this manner the advantage is attained that all these parts may be mounted on said wall outside the pump casing and afterwards he simultaneously inserted in their correct places by securing the partition in its place.

The embodiment above described and illustrated in the drawing is only to be regarded as an example, as it may obviously be modified in several ways in respect of its details, without departing from the principle of the invention. Thus it is possible, for instance, to locate the pump cylinders in only one single group or, if desired, in more than two groups, when thenumber of cam disks 22, 23 should, of course, be changed correspondingly. Also the number of pump cylinders in each group may naturally be altered as desired.

I claim:

1. In a multi-cylinder pump, compressor andthe like, the combination of a number of cylinders, each having a suction valve combine-d therewith, plungers movable in said cylinders, regulating means adjustable into different positions of regulation and adapted in such positions to cooperate with a different number of said suction valves to maintain the same permanently open, and governing means connected with said plungers so as to be driven with a speed corresponding to the movement of said plungers and adapted to actuate such suction valves which are not maintained permanently open by said regulating means in such manner that said suction valves are positively opened at the beginning of the suction strokes of I the corresponding plungers.

2. A pump according to claim 1 in which said cylinders are arranged in a number of groups, the plunger's, of the cylinders of whichare driven a'corrcsponding number of cranks on a crank shaft, and in which the governing means consist 'ofa number of rotatable cam disks corres i'n'ding tothe' number of cylinder groups, said'disks being displaced inrespect to one another m the same manner as said cranksand being connected with said crankshaft ins'uch manner as to rotate with the same speed as said crank shaft.

3. A pump according to claim 1 in which said governing means actuates said suction valves through the medium of push rods having heads which are adapted to raise the suction valves and are also. adapted to be actuated by the regulating means in such manner thatv the push rods corresponding to such suction valves as are maintained permanently open by said regulating means are also maintained raised up from said governing means.

4. In a multi-cylinder pump, compressor and the like, the combination .of a number of cylinders, each having a suction valve combined therewith, plungers movable in said cylinders, push rods adapted to actuate said suction valves, regulating means adjustmaintain the associated suction valves permanently open, governing means connected with said plungers so as to be driven with a speed corresponding to the movement of .said plungers and adapted to actuate such push rods which are not actuated by said regulating means in such manner that the associated suction valves are positively opened at the beginning of the suction strokes of the corresponding plungers, and a partition supporting said push rods and said governing means and detachably mounted in the pump casing.

5. In a multi-cylinder pump, compressor and the like, the-combination of a number of cylinders, each having a suction valve combined therewith, said cylinders being arranged in a number of groups, plungcrs movable in said cylinders,a crank shaft having a number of cranks corresponding to the number of cylinder groups and operatively connected with said plungers, regulating means adjustable into different positions of regulation and adapted in such positions to cooperate with a different number of said spect to one another in the same manner as said cranks on said crank shaft and being connected with said crank shaft in such man-- ner as to rotate with the same speed as said crank shaft, push rods adapted to actuate said suction valve s; said cam disks being adapted to cooperate with said push rods-so as to actuate such suction valves which are not maintained permanently open by said regulating ineans in such manner that said suction valvesare positively opened at the beginning'of the suction strokes of the corresponding plungers, and said push rods be-' ing provided with heads adapted to be actuated by the regulating means in such manner that the push rods corresponding to such suction valves asare maintained permanently open b said regulating means are also maintaine raised up from said cam disks. JOSEF SVARTZ. 

